docs: def remove_dependency(self, p_from_todo, p_to_todo, p_leave_tags=False):
          """ Removes a dependency between two todos. """
          dep_id = p_from_todo.tag_value('id')
  
          if dep_id:
              self._depgraph.remove_edge(hash(p_from_todo), hash(p_to_todo))
              self.dirty = True
  
          # clean dangling dependency tags
          if dep_id and not p_leave_tags:
              p_to_todo.remove_tag('p', dep_id)
  
              if not self.children(p_from_todo, True):
                  p_from_todo.remove_tag('id')
                  del self._parentdict[dep_id]